mandoc tbl support

Hi all,
I've just committed the updates for mdocml to 1.10.9. This features the
integrated tbl(1) engine, which is still a bit rough, but creates at
least basic text and HTML output. You can get cat pages formatted with
mandoc by setting MKMANDOC=yes. HTML pages are formatted with mandoc by
default. Please report problems if you see errors in output or man pages
incorrectly getting rejected.
Joerg